He was to be sought for, to be hunted out, to be produced; and this change accordingly gave rise to a new branch of commerce.
Some time before 1454 a Portuguese factory was established at one of the Arguim islands, and this factory soon systematized the slave-trade.
Thither came all kinds of merchandize from Portugal, and gold and slaves were taken back in return; the number of the latter sent home annually, at the time of Ca da Mosto's visit in 1454, being between seven and eight hundred.
The narrative of the Portuguese voyages along the African coast is, for the most part, rather uninviting.

It abounds with names, and dates, and facts; but the names are often hard to pronounce, the dates have sometimes an air of uncertainty about them, and the facts stand out in hard relief, dry and unattractive.

Could we recall, however, the voyagers themselves, and listen to their story, we should find it animating enough.

Each enterprise, as we have it now, with its bare statistics, seems a meagre affair; but it was far otherwise to the men who were concerned in it.

Of the motives[4] impelling men to engage in such expeditions, something has already been said.
[Footnote 4: "They err who regard the conquistadores as led only by a thirst for gold, or even exclusively by religious fanaticism.